This invention concerns compositions useful in cleaning up and removing residues from polymer manufacture, particularly the removal of uncured polyester, uncured epoxy resin and uncured polyurethane foam.
Various solvents have been used for decades in cleaning residues generated as a result of use of pains coatings, varnishes, sealants and so forth as well as residues generated during the manufacture of various polymers. It is known that certain solvents and solvent combinations which were once accepted as useful have come under scrutiny and increasing regulation by agencies at various levels of government for the health and environmental risks they pose. Accordingly, workers have continually desired to discover new solvents and solvent combinations capable of exerting adequate solvency characteristics on a variety of residues for the removal of such residues with at least the same degree of convenience as exhibited by the previously employed solvents.
The production of many products produced from polymeric materials and articles of manufacture derived therefrom generally involves the admixture of two or more materials. In the case of polyurethanes, by example, two subcombinations of materials are mixed together: a polyol and an isocyanate portion. The polyol typically contains ingredients such as plasticizers, catalysts, adhesion promoters, pigments, etc., and the isocyanate portion is typically neat isocyanate. Upon admixture of these subcombinations, polyurethane polymers are readily and rapidly formed, the reaction being nearly instantaneous. Owing to their versatility, polyurethane polymers may be caused to exist in several forms depending on the intended end use, including without limitation elastomeric strands, such as gasket materials, or various foams. Often, the polyol portion and isocyanate portion are pumped into a mixing fixture, such as a mixing head, in which they are subsequently combined or simultaneously projected onto a surface or into a mold. As in nearly all cases of reactive chemistry, there exists an optimum stoichiometric ratio of reactants which, if achieved, ensures that there is no excess of either starting material in the finished product. In the case of polyurethane, the reaction stoichiometry is one hydroxy group on the polyol molecule for each isocyanate group on the isocyanate molecule.
During the formation of polyurethane, as is also the case when materials in general which are capable of forming residues are mixed together, there exists a large window of opportunity for the sub-combination (e.g., the isocyanate and polyol portions) to be combined with one another in non-stoichiometric ratios, in addition to stoichiometric ratios. Organic residues produced by the stoichiometric and non-stoichiometric admixture of reactant subcombinations often render by-products which may be gummy and often gel-like, having cumbersome tenacity toward nearly all surfaces with which they come into contact.
Accordingly, manufacturers of various products have found it desirable from both the cleanliness and economic aspects to expend effort towards the development of methods for elimination or reduction of the formation of compounds (stoichiometric or non-stoichiometric) in locations other than the intended surface or mold. While such efforts have been successful in many cases to a high degree, there still exist circumstances in which it is necessary to have at hand a solvent or other chemical solution which can be applied to a cured or semi-cured urethane, epoxy or polyester or residue to assist in the clean-up and cause the polymer or residue to be readily wiped away with a cloth or brush. While several cleaning solutions for this application exist, they are often possessive of drawbacks which make their use undesirable. The undesirability usually stems from either a prohibitively high cost, health risk or environmental risk.
Similarly, industry is desirous of new, environmentally friendly compositions to remove uncured epoxy resin and uncured polyester (e.g., fiberglass) materials. These uncured resins often remain on application tools after use, for example.
If a family of compositions were available which was easy to prepare, were effective to remove uncured resin materials and which contained readily available ingredients of relatively low-cost that were not onerous to the environment or detrimental to the health of workers using the same, then such compositions would undoubtedly be welcomed by many users in the industry. The present invention provides such compositions.